It’s a parent’s worst nightmare to find your 20something son lying in his bedroom, unresponsive to your attempts to revive him. But when Martin, a 52-year-old consultant living in Boston, discovered his son K. in such a state, he knew what to do and had a critical tool on hand to help save his life.

That tool is naloxone (Narcan), a nontoxic and non-addictive drug that can reverse overdose from opioid drugs like heroin, Vicodin and Oxycontin. And a new study published in the Annals of Internal Medicine finds that distributing the drug to heroin addicts and their loved ones can save one life for every 227 naloxone kits distributed — and one for every 36 under more optimistic calculations.

Relying on data from existing naloxone distribution programs, the researchers found that for every 20% of heroin addicts in a population treated with the drug, about 6.5% of overdose deaths could be prevented, resulting in 2,000 lives saved in a population of 200,000 heroin users. Anywhere from 1 to 2 million Americans currently misuse heroin or prescription opioid drugs and could be in danger of an overdose.

Martin and his wife, Brigitte had discovered that their son was a heroin addict in September of 2011, after noticing a dramatic change in K’s behavior. They later learned that he had tried Oxycontin with some friends and almost immediately moved on to heroin.

When Brigitte realized that her son had a problem, she began attending meetings of Learn2Cope, a parent support group that teaches its members about dealing with their loved ones’ addictions. It was there that she learned about preventing overdoses with naloxone, which the group recently began distributing to people who have been trained in using the medication.

As of 2010, about 188 naloxone distribution programs exist in the U.S.— these groups have trained over 53,000 people and reported more than 10,000 overdose reversals.

Brigitte and Martin were among those trained, and although they had hoped never to put that training to use, consider themselves fortunate that on that night in 2011, they were able to take advantage of naloxone. When K did not respond to their attempts to rouse him, Martin shouted at K and slapped him, then tried rubbing his knuckles on his sternum as he’d been taught in the overdose training. K failed to wake up, so they administered the drug through the nose, continuing heart massage and rescue breathing.

Despite their fears that K might have gone without oxygen for too long to avoid brain damage, he woke up unscathed. “The immediate reaction of all the doctors was that if he hadn’t had that [naloxone], he wouldn’t have had a chance,” Martin says. As of now, K has been heroin-free for just over a year and is working as a mechanic.

“There are an unacceptable amount of deaths from overdose,” says Dr. Phil Coffin, director of substance use research at the San Francisco Department of Public Health and the lead author of the study. In an editorial accompanying the research, the director of the National Institute on Drug Abuse and two Food and Drug Administration (FDA) officials urge wider distribution of naloxone, noting that more than 38,000 people died of overdose last year alone, and hope that the study “represents a significant step in the evolution of the science in this area” by demonstrating the “robust” cost effectiveness of naloxone distribution.

According to the study, the cost of naloxone is well under the threshold that should justify its use — the drug costs $438 per quality adjusted life year (QALY), a measure that looks at not just how many years of life the drug can save but also how much it can improve the quality of that life. Generally, costs under $50,000 per QALY are considered economically sensible.

However, several major barriers still prevent greater access to the drug. “A key factor limiting widespread use of naloxone is that the only FDA approved formulation is injectable,” the authors of the editorial write. The intranasal naloxone used by Martin to save K is only available “off label” and is generic, meaning there is no commercial pressure to test it for approval so it could be made available cheaply without a prescription.

This puts the burden of finding naloxone, not to mention using it, on families of loved ones who may need it, and on programs like Learn2Cope, who face significant limits on the amount of the drug they can afford. “The cost of naloxone has gone up between threefold and tenfold in the last eight years,” says Coffin.

The study shows, however, that to anyone with a loved one at risk of overdose, like Martin and Brigitte, naloxone can be priceless.